Exercise bicycle



FIG. 1 is a bottom plan view of an exercise bicycle showing my newdesign;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof; and

FIG. 6 is a top plan view thereof.

The ornamental design for an exercise bicycle, as shown.